The purpose of the study is to evaluate the safety and immunogenicity elicited by combining MN rgp120 or bivalent AIDSVAX tm B/E vaccine with the adjuvant QS-21. To assess the safety of the two experimental vaccines when formulated with QS-21 or QS-21 plus Alum and to evaluate the immungenicity of the monovalent and bivalent HIV-1 candidate vaccine formulation with QS-21 or QS-21 plus Alum.